src/d_clisrv.c

@@ -1843,7 +1843,7 @@ static void CL_ReloadReceivedSavegame(void)
 
 	for (i = 0; i < MAXSPLITSCREENPLAYERS; i++)
 	{
-		camera[i].subsector = R_PointInSubsector(camera[i].x, camera[i].y);
+		camera[i].subsector = R_PointInSubsectorFast(camera[i].x, camera[i].y);
 	}
 
 	cl_redownloadinggamestate = false;

src/hardware/hw_main.c

@@ -3103,7 +3103,7 @@ static void HWR_RenderBSPNode(INT32 bspnum)
 		bsp = &nodes[bspnum];
 
 		// Decide which side the view point is on.
-		side = R_PointOnSide(viewx, viewy, bsp);
+		side = R_PointOnSideFast(viewx, viewy, bsp);
 
 		// Recursively divide front space.
 		if (HWR_PortalCheckBBox(bsp->bbox[side]))
@@ -3177,7 +3177,7 @@ static gl_vissprite_t *HWR_NewVisSprite(void)
 // Finds a floor through which light does not pass.
 static fixed_t HWR_OpaqueFloorAtPos(fixed_t x, fixed_t y, fixed_t z, fixed_t height)
 {
-	const sector_t *sec = R_PointInSubsector(x, y)->sector;
+	const sector_t *sec = R_PointInSubsectorFast(x, y)->sector;
 	fixed_t floorz = sec->floorheight;
 
 	if (sec->ffloors)

src/hardware/hw_portal.c

@@ -132,7 +132,7 @@ void HWR_PortalFrame(gl_portal_t* portal)
 	{
 		portalclipline = NULL;
 		portalcullsector = NULL;
-		viewsector = R_PointInSubsector(viewx, viewy)->sector;
+		viewsector = R_PointInSubsectorFast(viewx, viewy)->sector;
 	}
 }
 

src/p_mobj.c

@@ -3307,7 +3307,7 @@ boolean P_CameraThinker(player_t *player, camera_t *thiscam, boolean resetcalled
 	P_CheckCameraPosition(thiscam->x, thiscam->y, thiscam);
 #endif
 
-	thiscam->subsector = R_PointInSubsector(thiscam->x, thiscam->y);
+	thiscam->subsector = R_PointInSubsectorFast(thiscam->x, thiscam->y);
 	thiscam->floorz = tmfloorz;
 	thiscam->ceilingz = tmceilingz;
 
@@ -10354,7 +10354,7 @@ void P_PrecipitationEffects(void)
 		for (y = yl; y <= yh; y += RADIUSSTEP)
 			for (x = xl; x <= xh; x += RADIUSSTEP)
 			{
-				if (R_PointInSubsector((fixed_t)x, (fixed_t)y)->sector->ceilingpic != skyflatnum) // Found the outdoors!
+				if (R_PointInSubsectorFast((fixed_t)x, (fixed_t)y)->sector->ceilingpic != skyflatnum) // Found the outdoors!
 					continue;
 
 				newdist = S_CalculateSoundDistance(players[displayplayers[0]].mo->x, players[displayplayers[0]].mo->y, 0, (fixed_t)x, (fixed_t)y, 0);

src/p_setup.c

@@ -2338,7 +2338,7 @@ static void P_SetupCamera(UINT8 pnum, camera_t *cam)
 		cam->y = players[pnum].mo->y;
 		cam->z = players[pnum].mo->z;
 		cam->angle = players[pnum].mo->angle;
-		cam->subsector = R_PointInSubsector(cam->x, cam->y); // make sure camera has a subsector set -- Monster Iestyn (12/11/18)
+		cam->subsector = R_PointInSubsectorFast(cam->x, cam->y); // make sure camera has a subsector set -- Monster Iestyn (12/11/18)
 	}
 	else
 	{
@@ -2362,7 +2362,7 @@ static void P_SetupCamera(UINT8 pnum, camera_t *cam)
 		cam->y = thing->y;
 		cam->z = thing->z;
 		cam->angle = FixedAngle((fixed_t)thing->angle << FRACBITS);
-		cam->subsector = R_PointInSubsector(cam->x, cam->y); // make sure camera has a subsector set -- Monster Iestyn (12/11/18)
+		cam->subsector = R_PointInSubsectorFast(cam->x, cam->y); // make sure camera has a subsector set -- Monster Iestyn (12/11/18)
 	}
 }
 

src/p_user.c

@@ -3228,7 +3228,7 @@ void P_DemoCameraMovement(camera_t *cam)
 	democam.soundmobj = awayviewmobj_hack;
 
 	// update subsector to avoid crashes;
-	cam->subsector = R_PointInSubsector(cam->x, cam->y);
+	cam->subsector = R_PointInSubsectorFast(cam->x, cam->y);
 }
 
 void P_ResetCamera(player_t *player, camera_t *thiscam)
@@ -3263,7 +3263,7 @@ void P_ResetCamera(player_t *player, camera_t *thiscam)
 	thiscam->aiming = 0;
 	thiscam->relativex = 0;
 
-	thiscam->subsector = R_PointInSubsector(thiscam->x,thiscam->y);
+	thiscam->subsector = R_PointInSubsectorFast(thiscam->x,thiscam->y);
 
 	thiscam->radius = 20*FRACUNIT;
 	thiscam->height = 16*FRACUNIT;

src/r_bsp.c

@@ -1335,7 +1335,8 @@ void R_RenderBSPNode(INT32 bspnum)
 		bsp = &nodes[bspnum];
 
 		// Decide which side the view point is on.
-		side = R_PointOnSide(viewx, viewy, bsp);
+		side = R_PointOnSideFast(viewx, viewy, bsp);
+
 		// Recursively divide front space.
 		R_RenderBSPNode(bsp->children[side]);
 

src/r_fps.c

@@ -193,7 +193,7 @@ void R_InterpolateView(fixed_t frac, boolean forceinvalid)
 	viewcos = FINECOSINE(viewangle>>ANGLETOFINESHIFT);
 
 	viewplayer = newview->player;
-	viewsector = R_PointInSubsector(viewx, viewy)->sector;
+	viewsector = R_PointInSubsectorFast(viewx, viewy)->sector;
 
 	R_SetupFreelook();
 }

src/r_main.c

@@ -1080,7 +1080,8 @@ subsector_t *R_IsPointInSubsector(fixed_t x, fixed_t y)
 	while (!(nodenum & NF_SUBSECTOR))
 	{
 		node = &nodes[nodenum];
-		side = R_PointOnSide(x, y, node);
+		//side = R_PointOnSide(x, y, node);
+		side = R_PointOnSideFast(x, y, node); // this is fine since R_IsPointInSubsector is only used for precip spawn unless you disable noclipcam lol
 		nodenum = node->children[side];
 	}
 

src/r_main.h

@@ -74,6 +74,14 @@ extern lighttable_t *zlight[LIGHTLEVELS][MAXLIGHTZ];
 // Utility functions.
 INT32 R_PointOnSide(fixed_t x, fixed_t y, const node_t *node);
 
+// This is not as accurate
+// SHOULD NOT BE USED FOR ANYTHING GAMEPLAY RELATED!!
+FUNCINLINE static ATTRINLINE PUREFUNC INT32 R_PointOnSideFast(fixed_t x, fixed_t y, const node_t *node)
+{
+	// use cross product to determine side quickly
+	return ((INT64)y - node->y) * node->dx - ((INT64)x - node->x) * node->dy > 0;
+}
+
 FUNCINLINE static ATTRINLINE PUREFUNC INT32 R_PointOnSegSide(fixed_t x, fixed_t y, const seg_t *line)
 {
     fixed_t lx = line->v1->x;
@@ -94,6 +102,18 @@ fixed_t R_ScaleFromGlobalAngle(angle_t visangle);
 subsector_t *R_PointInSubsector(fixed_t x, fixed_t y);
 subsector_t *R_IsPointInSubsector(fixed_t x, fixed_t y);
 
+// uses R_PointOnSideFast
+// SHOULD NOT BE USED FOR ANYTHING GAMEPLAY RELATED!!
+FUNCINLINE static ATTRINLINE subsector_t *R_PointInSubsectorFast(fixed_t x, fixed_t y)
+{
+	size_t nodenum = numnodes-1;
+
+	while (!(nodenum & NF_SUBSECTOR))
+		nodenum = nodes[nodenum].children[R_PointOnSideFast(x, y, nodes+nodenum)];
+
+	return &subsectors[nodenum & ~NF_SUBSECTOR];
+}
+
 #define R_PointToDist(x, y) R_PointToDist2(viewx, viewy, x, y)
 #define R_PointToDist2(px2, py2, px1, py1) FixedHypot((px1) - (px2), (py1) - (py2))
 

src/s_sound.c

@@ -987,7 +987,7 @@ boolean S_AdjustSoundParams(const mobj_t *listener, const mobj_t *source, INT32
 		INT64 x, y, yl, yh, xl, xh;
 		fixed_t newdist;
 
-		if (R_PointInSubsector(listensource.x, listensource.y)->sector->ceilingpic == skyflatnum)
+		if (R_PointInSubsectorFast(listensource.x, listensource.y)->sector->ceilingpic == skyflatnum)
 			approx_dist = 0;
 		else
 		{
@@ -1000,7 +1000,7 @@ boolean S_AdjustSoundParams(const mobj_t *listener, const mobj_t *source, INT32
 			for (y = yl; y <= yh; y += FRACUNIT*64)
 				for (x = xl; x <= xh; x += FRACUNIT*64)
 				{
-					if (R_PointInSubsector(x, y)->sector->ceilingpic == skyflatnum)
+					if (R_PointInSubsectorFast(x, y)->sector->ceilingpic == skyflatnum)
 					{
 						// Found the outdoors!
 						newdist = S_CalculateSoundDistance(listensource.x, listensource.y, 0, x, y, 0);